In fighting structure fires, hose lines are commonlylaid along the means of egress for occupants of the building and passed through doorways. Normally, in high rise buildings the standpipe hose outlet is located in the stairwells which serve as means of egress for the occupants of the building during a fire. The fire hose is connected to the standpipe (which serves as its water supply) and must be laid through a doorway (normally a fire door) to the fire floor. As a result, the fire door which is designed to keep the staircase free of heat and smoke by containing the fire on the fire floor, is necessarily propped open hence defeating its intended purpose and allowing the means of egress, especially the floors above the fire floor, to be flooded with heat and smoke.
In the past various proposals have been made to solve this problem, for example, relocating the hose outlet from the stairwell side of the fire door to the other side of the same, normally in a main hallway just inside the fire door. This solution, however, poses other problems. One such problem is that the fire fighter must now enter the fire area without a charged fire hose. This normally is not considered a safe practice, even if it is feasible in a particular situation. In many situations this may not be feasible because the fire area (the area on the fire side of the fire door) may be so charged with heat and smoke as to make locating and connecting to the standpipe hose outlet difficult if not impossible. The solution to this problem normally would be to use the standpipe hose outlet on the floor below the fire floor (in a high rise stairwell) and then lay the hose up one flight of stairs and through the fire door to the fire. This solution has the effect of causing two fire doors to be propped open with potentially unfortunate results.
Another proposed solution to the problem of entering the fire floor with a connected hose line without compromising the means of egress, is to install a second fire door near the first one. The hose outlet could be located in the vestibule that would be created between the two doors. This solution, however, has two major disadvantages. The first and most obvious is the cost. Hose outlets would still have to be relocated from the stairwell landing to the hallway (in the case of existing structures) and in addition, a second fire door would have to be installed adjacent to each hose outlet. This, of course, would be an inconvenience during normal everyday use, since occupants then would open two doors rather than just one. The second disadvantage is the small work space fire fighters would have in such a hallway/vestibule when connecting hoses to the standpipes. Fire fighters would still be unable to charge the hose line before entering the fire floor (through the second door) due to the very limited space. If fire fighters felt it was necessary to charge the hose before entering, they would have to pass it through the first fire door into the stairwell and then back through the door again, into the vestibule, and through the second doorway. This, of course, would result in propping open both doors and defeat the purpose of the second door.